Bacterial community in cold and alkaline environments of Hoh Xil basin in Qinghai–Tibet Plateau and isolation of potential sources of microbiota

Abstract

The Hoh Xil basin is the largest Cenozoic sedimentary basin in the Qinghai–Tibet Plateau (QTP) with an average altitude of above 5000 m. It is also the coldest region in the QTP. However, due to the difficulty of sample collection caused by the harsh natural environment, a limited number of studies have been conducted on soil microorganisms in this region. We used culture-dependent and independent methods to investigate the bacterial communities in desert soil (n1), saline–alkali land (n2), saline–alkali wetland (n3), and soda lake sediment (n4). The results showed distinct bacterial communities between different environmental types. We found that the Chao1 and Shannon diversity indices of n1 were significantly lower than those of n4 (P < 0.05). At the phylum level, all samples were dominated by representatives of Proteobacteria, Bacteroidetes, and Actinobacteria, which were similar to the findings of previous studies on the desert soil in the same region. Moreover, we identified 10 strains of bacteria from 109 isolates, most of which belonged to Pseudomonas (90.8%). The growth of the isolate k9 was optimal at a high pH value (pH 10.0) and a low temperature (5 °C), and this stain could produce extracellular enzyme (alkaline phosphatase, acid phosphatase, and naphthol-AS-BI-phosphohydrolase) under alkaline (pH 10) and cold (5 °C) condition. These results demonstrate the diversity of bacteria in the Hoh Xil basin and identify potential psychrophilic and alkaliphilic bacteria with multiple types of extracellular enzyme activity.

Notes

Funding

This work was supported by the National Natural Science Foundation of China (No. 31600409), the Open Project of Qinghai Provincial Key Laboratory of Crop Molecular Breeding (2017-ZJ-Y14), the CAS “Light of West China” Program, the National Science and Technology Foundation Project (2015FY110100), and the Strategic Priority Research Program of Chinese Academy of Sciences (XDA2005010406).

Compliance with ethical standards

Conflict of interest

The authors declare that they have no conflict of interest.

Research involving human participants and/or animals

This article does not contain any studies with human participants or animals performed by any of the authors.

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